Falling film type of vacuum still with rotating partial condenser



1952 A. w. GOLDSBARRY ET AL 2,613,176

FALLING FILM TYPE OF VACUUM STILL WITH ROTATING PARTIAL CONDENSER Filed Dec. 26, 1947 2 SHEETS-SHEET 1 I FIG. l INVENTORS.

. ALBERT W. GOLDSBARRY BY MEYER S. AGRUSS HTTOIZNE Y.

06L 1952 A. w. GOLDSBARRY ET AL 2,613,176

FALLING FILM TYPE OF VACUUM STILL WITH ROTATING PARTIAL CONDENSER Filed Dec. 26, 1947 2 SHEETS-SHEET 2 INVENTORS. ALBERT W. GOLDSBARRY BY MEYER $.Asauss (My f HTTOR j Patented Oct. 7, 1952 FALLING FILM TYPE F 1 VACUUM sTILI; WITH ROTATING PARTIAL CONDENSER Albert W. I Gold sbarry, Narnia-boa; an Meye s.,'.; g Agruss, Chicago, 111., assignors to Th'e'Pure 0il, v,

" v Companm Chica'go, IlL, a corporationofohioit Application December 26, 1947, Serial-No. 793396 This invention relates to an improved apparatus for the distillation and'fractionation at 'a reduced-pressured complex mixturesof liquids and solids capableof -beingTliquefi'ed'upon heat-- ing, such as hydrocarbon"mixtures comprising said c nd n a e ta s D 3 there-being Obtained petroleum, r f. V by this action. sharpfractions' of liquid mixtures, More particularlmfthe .(appa'ratus comprises p'articularly. when the distillation is carried .out centrifugalequiphientliorfractional distillation at reduced pressures. of a mixture df fhighfniol'ecular weight oils and One embodimentof the invention is illustrated waxes of the type encii'un'te'red in the lubricating in the accompanying dravvingsin which: 7 on processing art, where the material is spread N Figure-"1 is alongitudinal section through the into a thin film and "b'i'ected to centrifuging apparatus showing the arrangement of tubular while itis'distilled u r reduced pressure and members to define the coaxial annular spaces in maintained in "counter cur'rent I contact with which the distillation is carried out; vapors -thereof. p H I Figure 2 is a section through the apparatus 'It is a'ifund'a'entalohject of theiinvention to v takcnat the levelof line 2-52 in Figure 1; provide an 'im mve'araii ng film type distilling Figure 3 is an enlarged longitudinal section of apparatus for thes'harp fractionation of liquid the upper, portion or the rotating condenser mixtures, arranged in the continuous heating, 'showingadetail ofthecondensingtubesupport; fractionation andv ensatio'n of 1 the fluid 0 Figure s'an'enlarged sectionof the apparatus during'th'e damnation thereof; g V taken on thelinefd- -fi or Figure 3 to ShOW detail; A second'obj'ect oithe'invention is to provide Figure 5, is an enlarged sectional view of the a unitary structure for the distillation of fluids bottom of the condensing tube support to show in which the fluid ccindTensate is subjectedto detail thereof; I centriiugal'forceiand the heatinput is'efficiently 2D Figurs dfl, and Bare "enlargedpartial section 5 a efi r Views of tube 32 showingspiral,circumferential, Anotherobject isto-provide an apparatus and and longitudinal cor ugations on the external method iorohtaining' imprbved -fractionation of surface thereof. t oilmiiiturefs otherwise diificult to distill without In Figure 1 where there is shown a preferred Cracking w H r 1 embodimentof the invention, I It represents-the A f-urtlier object o'f the'=invention is to provide still pot having an inlet H and "an outlet '12, means for using the liquid being distilled as a controlled by'a valve 13. Liquid to be distilled heat transfer medium for heating 'the column, is retained in the pot while-being heated'to'furin "which operation the sliquidispirculated -to nish vapors to the apparatus. The heating can effect the requisite heating and cooling of the be accomplished by electrical or other heating evaporating and*chiidensing 'surfaces which are means I98 to supplement such pre -heating' of coaxially arranged in thecolumn. l I the fluid as may be carriedout in external heat- Other'ob'jects andadvantages of the invention ing apparatus. Extension 14 on pot H) termiw'ill in part be obviousa'nd in part appeariherehating in ffiange i5 constitutes an exit for jnafte 40 vapors and serves the purpose of receiving and The invention comprises. a fractionating" colholding fr i nating, tower 16 on the potuf umnenclosing a condenser for employment with e pot 0 is provided at a convenient section a still, which column includes a series of co.- thereof with a cover plate I! held in place by axially arranged cylindrical :members providing b lts, 18. and 9 overa-n Opening through hich annular passages for distillate vapor, condensate, access to the interior of the i can be had. feed'and.:heatingmedium, so that'circulation of For the purpose, of circulating. heated jfluid heating fluid through *an annular space in: the through theapparatus to accomplish heating and column will-accomplish theheating necessary for condensing in the fashion, desired, the pot I!) the distillation. The apparatus is'also arranged is alsoequipped with an internally disposed pump to permit the circulation of some relatively cool, 20 which is driven from the outside by means fluid through the-innermostcondensing portion of a shaft 25 which s b into the 901740 of thecolumn to provide for condensation of through a bellows '22 supported on a flange 23; some of theproduct. 'Ifhe apparatus thus com The driving unit used to operate the pump prises a falling iilm t-ypeof column employing should beselected to suit the load and material ti rans d sn e q a abl par l c d ns beingdistilled. L l

spleen (cratees which is cooled by the ?falling film flowing over;

the interior surface of said condenser, as a conse" quenceof which condensate collects on the outer surface thereof and isc entriiugally flung to the hot outer column wall, where revaporization of I Liquid which is int-he pot submerges the pump and on each delivery stroke thereof, liquid passes from the pump 20 into line 26, controlled by valve 21, and line 28 for feeding into the fractionating tower at junction point 29.

The fractionating tower I6 comprises three coaxially arranged cylinders 30, 3| and 32, which are supported together with shaft 33 to define heating medium annulus 34, vapor annulus 35, and condensing liquid annulus 36. The inner surface 31 of the tube 30 and outer surface 38 of tube 3| define the heating liquid annulus 34; similarly, vapor annulus 35 is defined by the inner surface 39 of tube 3| and the outer surface 40 of tube 32. An annular passage for cooling liquid is defined by the inner surface M of tube 32 and the shaft 33. The entire assembly is supported on flange I with collar 42 integrally joined to tube 30 and terminating in flange 43 to match flange I5 on the still pot, which, in the final assembly, are bolted together with a sealing gasket therebetween. Supports 44 and 45 maintain the several tubes in proper alignment.

Tubes 30 and 3| are connected together at their lower extremities and at the upper extremity of tube 30 to define annular space.34 for heating fluid, which is admitted by conduit 28 and is led out by conduit 46.

An inlet oil feed pipe 41 is located above the large flange I5 to pass oil feed into the annular space 48 which opens into the still and is defined by the collar 42, flange 43, extension I4, flange I5 and tube 30.

The internal pump 20 transfers the hot contents of the still directly to the annular space 34 which is between the outermost and the second tube as shown in the drawing. This space, it will be noted, does not extend completely to the top of the column, but ends shortly above the top of tube 32. A separate annular space 49 defined by tube 31 and tube 50, surrounds the upper portion of the column, and receives oil from outlet pipe 46 which is circulated therethrough by way of conduits 5| and 52. According to the demands of the distillation being conducted, liquid in passingfrom space 34 to 49 may be heated or cooled. Suitable heat exchange means as illustrated by heat exchanger I09 may be employed for this purpose. When the oil emerges from this second annular space, it may again be adjusted in temperature by suitable heat exchange means IIO before it is passed to the group of conduits feeding the interior of the rotating partial condenser.

The annular space 35 defined by tubes 3| and 32 constitutes a vapor space in direct communication with the still pot I0 through which vapors generated in the pot rise and find their way to conduit 53 to pass to a totalcondenser, not a part of the fractionating apparatus shown. Conduit 53 also provides for connection to a pump for evacuating the apparatus.

Tube 32 and shaft 33 define a third annular space 36 which is the cooling liquid space for making the outer surface 40 of tube 32 a condensing and revaporizing surface, as will be explained in greater detail in the description of the operation of the apparatus. Tube 32 terminates near the upper portion of the apparatus and telescopes with a narrower tube 60, which in turn enlarges in diameter at its upper end to define a housing 6| around the upper portion of shaft 33. The housing receives cooling liquid through conduit 62 so that it can fiow down the inner surfaces of tubes 60 and 32 in the form of tube is merely suggested, for other drive mechanisms which will furnish desired speeds of rotation arev adequate. As can be seen, the assembly is supportedon the upper end of the column by flange 8| and the several concentric tubes are supported in alignment with the outer tube 30 by meansof fixed connections and by connecting flanges and BI together with bolts. A sealing gasket is included between members 63 and II and 8|; v

In Figure 3, where there is shown in detail the -telescoping arrangement of tubes, central shaft 33 and -tubes 32 and GI) are shown and identified. Tube 60 is shown with a beveled lower edge which serves to promote smooth flow of liquid film thereoven. Below the upper end of tube 32, a small collar and set screws 9| and 92 hold a pyramidal distributing piece 93 in position on the shaft. The piece, which may be integral with tube 32 or merely closely fitted therein, has a plurality of orifice-defining cuts 94 arranged around its periphery so that liquid flowing as a film over th inner surface of tube 60 and down through the annulus defined by shaft 33 and tube .32 will be distributed over the pyramid and passbut through the orifices and down over the inner surface of tube 32 as a film.

Figure 4 shows a plan view of the pyramidal piecetaken at the level corresponding to line 44 in Figure 3.

Figure 5 is an enlarged section of the lower termination of the shaft 33 and support for tube 32. Essentially, this portion of the apparatus is a threaded section I 00 which will receive a nut IIII for locking an umbrella member I02 in place, which member is locked or integrally joined with the end of tube 32. Around the periphery of the tube 32 there is a series of slots I03 which defines orifices in cooperation with the umbrella section.

Shaft 33 terminates at the level of supports 44 and 45 for the shaft 33 and is held in place by bearing I04 including races I05 and I06 and plate II", as shown in Figure 1.

In operation, the arrangement is such that central shaft 33 can be rotated at a controlled rate of speed through a very wide range to apply centrifugal force to the film of liquid condensate on the outer surface of tube 32. Application of motive power to frame 12 and magnet I3 will cause corresponding rotation of magnet III and shaft 33.

In performing a distillation, the mixture to be fractionated is charged through conduit II to the still III where it is initially heated under a selectedreduced pressure to a temperature sufficient to cause boiling to begin, whereupon, by means of internally positioned pump 20, the charge is circulated first to the annular space 34 in the column I6, which is a wall heater space. The liquid flows out of the heater space through conduit 46 and, thereafter, through a cooling coil f i s des red I' o er the temperature thereof.

to. theupper annular heate pace toughconduit 5l after which it-passes out through conduit .52 and. throu h e e c l for adjust-1 ment. of its temperature in the desireddirection. The liquid isthen passed through, line- -fizeinto the upper end of the interior of the rotatingpartial condenser comprising tubes 32 and fiqnwhere it passes downwardly through the; rotating meme ber as a falling film whereby it picks up heatfrom, the vapors generated in, the still and rising in space 35. After passing. through the condenser, the liquid emerges from the lower end of the rotating member as a spray. formed .over member 802 to contact directly the vapors in the still beforerejoining the main body of oil at atemperature substantially that of the vapors rising therefrom. The main body of oil having been subjected to a selected temperature-pressurerela e. tionship which induces continuous and sustained evaporation at the desiredrate, and tlrelcycling of the still charge having been continuedjat. the desired and controlled flow-rate necessary, to effect properly the completion offits fractionation, the distillation is accomplishedunder a state of dynamic equilibrium, while the heat content of the fluid is maintained or progressively raised as demanded by the progress of the fractional distillation.

The course of liquid through the apparatus during the distillation in a typical case would be as follows: i I

Pre-heated feed would enter through conduit H or conduit 41 to join the body of liquid maintained in the still pot 10. Pump 20 forces liquid through lines 26 and '28. ,to annularwall heating space 34, from which they liquid emergesthrough conduit 46 to go through a cooling" or heat-ing coil, depending upon the temperatureadjustment de,-. sired, to enter conduit 51, circulate, through heating space 49, and emerge through conduit 52'. From this point, the liquid, againdepending upon the temperature adjustment desired, can pass, through a cooling or heating zone to be fed into conduit 62, which is the entry point for cooling liquid for the rotating condenser. The liquid accumulates in the housing 6| to a moderate level and passes down through the interior of tube 60 as a layer on the interior surface thereof, to be spread onto the interior surface of tube 32, which is the active rotating condenser portion of the apparatus. The cooling liquid emerges from the bottom of tube 32 as a spray to rejoin the main body of liquid in the pot.

Similarly, the course of vapors is readily traced through the apparatus, for vapors enerated within the apparatus rise and pass up through the annular space 35 where they are heated by the liquid in the outer wall heating space 34 and cooled by the surface of rotating condenser 32. The continuous contact of these vapors with these two surfaces results in the condensation of some vapor on the surface of tube 32 and its separation therefrom by centrifugal force to be thrown across the annular space through the rising vapors to contact the interior wall 39 of tube 3!, where the liquid is re-heated and re-vaporized to pass through the cycle again. Thus, it can be seen that in the passage through the vapor space, liquid will be vaporized, condensed and r'e-vaporized a number of times to accomplish a sharp fractionation thereof. Those vapors which finally reach the top of the column pass out through line 53 for total condensation.

If it is desired, the outer surface of rotating introducing vapors into the bottom of said vapor sin e area and. to. assistin. rea n up the descending film, of condensate to throw it on tov he .'heatecl; 0 umnwall- This is shown in Figures, 6, 7, and 8-,wherein, these corrugations are shown; in theform of ribs. Since tube 32 is adapted; to expose anefficient heat transfer surface it is; desirable-that the. corrugations shown in -Eigures 6,7, and 8 do not add to the tube .wall

thickness. Thus, the entirewall structure of tube 32-;may; be, corrugatedso that the inner surface is,also;furrowedorwcorrugated.

Itshollld-be noted that the course of the heating; liquidapplied; tothe double wall column may be;;varied for the, liquid, being distilled can be pumped from, apre-heater into the heating annulus or taken, directly from the pot into the columniacket andv thence, if cool enough, into the-interioror the rotatingpart of the condenser. The-particular: route selected for thecirculation f; the. liqu dthrqugh. the. heatin -co lin cycl is optionalfor, itcan; readily be seen that variat onsthere f canbework d' ut- Though: the description of the invention has beenconfined to a singlespecific embodiment of the;-invention,,it should be apparent that certain changes; may be made in the, construction anddifferent embodiments of the invention could be,. made iwithout departing from the scope thereof. It; is, intended, therefore, that all matten containedin theabovedescription, or shown in the accompanying drawing, shall be interpreted as illustrative; andnotin a limiting sense.

Whatis claimed-isza i 1. A fractionating;column comprising a plurality of concentrically supported: conduits denin a plurality. of annuli, a central shaft rota-tably supporting at least, the-innermost one of said conduits,v rotational driving means con nected tosaid shaft, cooling. liquid conduit means in ptelescopic relationship; with the inner portion of the; upper. end; ofisa-id innermost concentric conduit, cooling liquid dispersion means within. the top of said innermost concentric conduit providing a falling film of cooling liquid on the inner surface of said innermost conduit, circumferential ports along the bottom periphery of said innermost concentric conduit, a supporting and cooling liquid dispersing means attached to the lower portion of said shaft and impinging in supporting relationship on the bottom periphery of said innermost conduit, the concentric arrangement of the innermost conduit and the surrounding one defining a vapor space, means for space, the two concentric conduits next adjacent to said innermost conduit being joined adjacent their lower ends to define a liquid holding space, means to charge liquid to said space, said supporting and cooling liquid dispersing means being adjacent the point of entry of vapors into said vapor space and said last mentioned dispersing means being positioned to cooperate with said ports to discharge liquid from said space into the path of ascending vapors entering the bottom of said vapor space.

2. A fractionating column comprising inner, intermediate and outer conduits concentrically arranged and supported, wherein the inner conbeing also the means of the intermediate conduit is supported-and joined vapor space, means for introducing vapors'into' the bottom of said vapor space, 'means for rotating said shaft and inner conduit, conduit means for introducing liquid to be distilled into the interior of said inner conduit'to cool the surface thereof, means for passing heating liquid through the annulus formed by said intermediate and said outer conduits, said lowermost coniform dispersing means being positioned to cooperate with said circumferential ports to discharge liquid to be distilled into thep'ath'of said vaporsent er ing the bottom of said vapor spacef 3. A falling film distilling column comprising an inner, intermediate and outer conduit concentrically arranged, said intermediate and outer conduits being joined adjacent their lower ends to form a heating liquid'holding'annulus; means to charge liquid to said liquid annulus, said inner" and intermediate conduits being held in fixed space relationship to define a vaporannulus, means to charge vapors'to be fractionated into the bottom of said vapor'annulusfsaid inner conduit terminating below the top of said outer conduit and having circumferential ports along its bottom periphery, a central rotatable shaft extending the length of said column, said'shaft supporting said inner conduit by means of a coniform cooling liquid-dispersing means attached to the bottom of said shaft and impinging in supporting relationship on said bottompe'riphery, cooling liquid conduit means in telescopic relationship with the inner portion of the upper end of said inner conduit, said conduit means being flared into a cooling liquid reservoir at its upper end concentric with said shaft and forming a restricted liquid annulus between its inner surface and said shaft, a second coniform 7 support for said inner conduit at its circumferentially'ported periphery,-

. 8 cooling liquid-dispersing means attached to'said shaft within said inner conduit in contact with the inner surface thereof below its upper terminus and below thelower end of said cooling liquid conduit means, said second dispersing means having ports along its outer periphery to provide passage for a falling liquid film from said liquid annulus and disperse same on the inner surface of said inner conduit when under the influence of centrifugal force.

ALBERT W. GOLDSBARR-Y. MEYER S. AGRUSS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,040,837, DYarmett May 19, 1936 2,169,601. Cornelius d. Aug. 15, 1939 2,202,008 Ittner May 28, 1940 2,224,621 Voorhees Dec. 10, 1940 2,333,712 Eckey Nov. 9, 1943 2,403,978 Hickman July 16, 1946 2,427,594 Deny Mar. 9, 1948 2,539,699 Perry et al. Jan. 30, 1951 FOREIGN PATENTS Number Country Date 595,096 Great Britain Nov. 26, 1947 595,142 Great Britain Nov. 27, 1947 596,392 Great Britain Jan. 2, 1948 OTHER REFERENCES Byron et al.: A Universal Rectifying Column, American Chemical'Society, Abstracts of Papers, 108th Annual Meeting, Sept; llt'o 15, 1944, Division of Petroleum Chemistry, pages 1-0 and 2-0.

Birch et al.: Spinning Band ColumnfFebv 1947, Journal of Soc. of Chemistry.

Morse: High Vacuum Technology," Ind. 8:

Eng Chem, Sept. 1947, vol. 39,'No. 9. 

1. A FRACTIONATING COLUMN COMPRISING A PLURALITY OF CONCENTRICALLY SUPPORTED CONDUITS DEFINING A PLURALITY OF ANNULI, A CENTRAL SHAFT ROTATABLY SUPPORTING AT LEAST THE INNERMOST ONE OF SAID CONDUITS, ROTATIONAL DRIVING MEANS CONNECTED TO SAID SHAFT, COOLING LIQUID CONDUIT MEANS IN TELESCOPIC RELATIONSHIP WITH THE INNER PORTION OF THE UPPER END OF SAID INNERMOST CONCENTRIC CONDUIT, COOLING LIQUID DISPERSION MEANS WITHIN THE TOP OF SAID INNERMOST CONCENTRIC CONDUIT PROVIDING A FALLING FILM OF COOLING LIQUID ON THE INNER SURFACE OF SAID INNERMOST CONDUIT, CIRCUMFERENTIAL PORTS ALONG THE BOTTOM PERIPHERY OF SAID INNERMOST CONCENTRIC CONDUIT, A SUPPORTING AND COOLING LIQUID DISPERSING MEANS ATTACHED TO THE LOWER PORTION OF SAID SHAFT AND IMPINGING IN SUPPORTING RELATIONSHIP ON THE BOTTOM PERIPHERY OF SAID INNERMOST CONDUIT, THE CONCENTRIC ARRANGEMENT OF THE INNERMOST CONDUIT AND THE SUR- 